• 한국작물학회지
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• 제47권5호
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• pp.384-389
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• 2002

No-tillage (NT) practice for corn production has advantages of reduction of soil erosion and energy conservation. Research on effects of NT for sweet corn or super sweet corn is very limited. Hybrids of sugary (su) and shrunken-2 (sh2) were tested under NT and conventional tillage (CT) practices to investigate plant characters, ear characters, fresh yield, and grain yield. Sugary hybrids were Golden Cross Bantam 70 (GCB70), Sprint, Geumdanok, and Danok3. Shrunken-2 hybrids were BSS9472, Cambella90, GSS9299, Jubilee, KS-Y-65, and Chodangok1. Emergence rates under NT were lower than those under CT for su, while there was no difference between tillage systems for sh2. There were no differences between CT and NT for days to tasseling and silking, plant height, and ear height for both su and sh2. Ear characters such as ear length, number of kernel rows, number of kernels per row, and t100-kernel weight under NT were not significantly different from those under CT. There were no differences between two tillage practice for fresh and grain yield, rather they showed trend of increases under NT practices. Results from this trial indicate that NT practice for both su and sh2 cultivation may be possible to recommend to farmers.

• 한국작물학회지
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• 제45권1호
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• pp.55-58
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• 2000

Germination of sweet and super sweet corn is lower than normal corn due to the higher sugar and lower starch contents of kernels. Sweet corn seeds are easily deteriorated in the field under the unfavorable condition, therefore it is important to identify the optimal harvesting time for seed production. This trial was conducted to investigate the responses of germination percentage of shrunken-2(sh2), brittle(bt), sugary(su), and sugary enhancer(se) hybrids in relation to harvesting dates. Eight hybrids of four different gene sweet corns were harvested at 15, 20, 25, 30, 35, 40, 45, and 50 days after silking(DAS). Germination test was performed using paper towel method. Mean germination percentages across eight hybrids showed the highest value at 45 DAS. There were significant differences among genes and within gene for germination. Shrunken-2 hybrid Mecca was higher than su hybrids for germination, indicating that sh2 would not be poorer than su Late harvesting beyond the optimal harvesting date might not be desirable because of more lodging and ear rots. Theoretical optimal harvesting date estimated from the regression equation was 40.9 DAS, however, practical date for harvesting would be a few days later than the estimated date if seedling vigor might be considered. Kernel dry weight per ear showed similar response to germination. Regression equation showed the highest kernel dry weight at 40.7 DAS. Significant correlations between kernel dry weight and germination were observed, impling that kernel dry matter accumulation would be an important factor for germination.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.107-107
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• 2017

Sweet corns are enjoyed worldwide as processed products and fresh ears. Types of sweet corn are based on the gene(s) involved. The oldest sweet corn type has a gene called "sugary (su)". Sugary-based sweet corn was typically named "sweet corn". With its relatively short shelf life and the discovery of a complementary gene, "sugary enhanced (se)", the sweet corn (su only) was rapidly replaced with another type of sweet corns, sugary enhanced sweet corn, which has recessive homozygous su/su, se/se genotype. With the incorporation of se/se genotype into existing su/su genotype, sugary enhanced sweet corn has better shelf life and increased sweetness while maintaining its creamy texture due to high level of water soluble polysaccharide, phytoglycogen. Super sweet corn as the name implies has higher level of sweetness and better shelf life than sugary enhanced sweet corn due to "shrunken2 (sh2)" gene although there's no creamy texture of su-based sweet corns. Distinction between sh2/sh2 and su/su genotypes in seeds is phenotypically possible. The Involvement of se/se genotype under su/su genotype, however, is visually impossible. The genotype sh2/sh2 is also phenotypically epistatic to su/su genotype when both genotypes are present in an individual, meaning the seed shape for double recessive sh2/sh2 su/su genotype is much the same as sh2/sh2 +/+ genotype. Hence, identifying the double and triple recessive homozygous genotypes from su, se and sh2 genes involves a testcross to single recessive genotype, chemical analysis or DNA-based marker development. For these reasons, sweetcorn breeders were hastened to put them together into one cultivar. This, however, appears to be no longer the case. Sweet corn companies began to sell their sweet corn hybrids with different combinations of abovementioned three genes under a few different trademarks or genetic codes, i.g. Sweet $Breed^{TM}$, Sweet $Gene^{TM}$, Synergistic corn, Augmented Supersweet corn. A total of 49 commercial sweet corn F1 hybrids with B73 as a check were genotyped using DNA-based markers. The genotype of field corn inbred B73 was +/+ +/+ +/+ for su, se and sh2 as expected. All twelve sugary enhanced sweet corn hybrids had the genotype of su/su se/se +/+. Of sixteen synergistic hybrids, thirteen cultivars had su/su se/se sh2/+ genotype while the genotype of two hybrids and the remaining one hybrid was su/su se/+ sh2/+, and su/su +/+ sh2/+, respectively. The synergistic hybrids all were recessive homozygous for su gene and heterozygous for sh2 gene. Among the fifteen augmented supersweet hybrids, only one hybrid was triple recessive homozygous (su/su se/se sh2/sh2). All the other hybrids had su/su se/+ sh2/sh2 for one hybrid, su/su +/+ sh2/sh2 for three hybrids, su/+ se/se sh2/sh2 for three hybrids, su/+ se/+ sh2/sh2 for four hybrids, and su/+ +/+ sh2/sh2 for three hybrids, respectively. What was believed to be a classic super sweet corn hybrids also had various genotypic combination. There were only two hybrids that turned out to be single recessive sh2 homozygous (+/+ +/+ sh2/sh2) while all the other five hybrids could be classified as one of augmented supersweet genotypes. Implication of the results for extension service and sweet corn breeding will be discussed.

• 한국작물학회지
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• 제51권7호
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• pp.632-638
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• 2006

단옥수수와 초당옥수수 종자의 활력을 높일 수 있는 탈곡방법을 알기 위하여 단옥수수($Early\;Sunglow{\times}GCB\;70$)와 초당옥수수($Xtrasweet\;82{\times}Fortune$) 종자의 수분함량을 12, 15, 18, 21%로 건조한 후 손과 전기 탈곡기로 탈곡하여 $25^{\circ}C$ 발아율, cold test에서 출아율, 당 및 전해질 누출, ${\alpha}-amylase$ 활성 등 종자특성을 조사한 결과를 요약하면 다음과 같다. 1. 손 탈곡은 종자수분 함량에 관계없이 기계적 상처가 없었으나 기계 탈곡할 때 종자의 상처를 줄일 수 있는 수분함량은 단옥수수는 $15{\sim}21%$, 초당옥수수는 $12{\sim}21%$이었다. 2. Cold test에서 출아율은 종자수분 함량에 관계없이 손 탈곡한 종자가 기계 탈곡한 종자보다 단옥수수는 $6{\sim}14%$, 초당옥수수는 $9{\sim}18%$ 높았다. 3. 단옥수수는 $25^{\circ}C$ 발아율과 cold test 출아율과 정의 상관이 있었으나 초당옥수수는 관계가 없었다. 단옥수수와 초당옥수수의 cold test에서 출아율은 침종 시 당 누출과는 부의 상관, ${\alpha}-amylase$ 활성과는 정의 상관이 있었다. 4. 기계 탈곡 시 $25^{\circ}C$에서 상처립 비율, 발아율, cold test에서 출아율, 당과 전해질 누출량, ${\alpha}-amylase$ 활성을 고려한 적정 종자수분 함량은 단옥수수는 15%, 초당옥수수는 12%이었다.

• 한국작물학회지
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• 제46권2호
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• pp.69-77
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• 2001

'Chalok 1/Cooktail 51' corns, supersweet corn gene controlled by either brittle-l (bt l) or shrunken-2(sh2) gene introduced into waxy corn, showed agronomic characteristics between supersweet corn and waxy corn. The ears were harvested at different development stages from 15 to 35 days after silking (DAS). Ear diameter of Cocktail 51 and 'Cocktail 51'/Chalok 1 increased from 15 DAS to 30 DAS and little increased thereafter, but that of Chalok 1/Cocktail 51 and 'Chalok l' increased until 35 DAS. Diameter of ear extension increased more in Cocktail 51 and Chalok 1/Cocktail 51 corn than Chalok 1. Ear fresh weight of Cocktail 51 decreased later 30 DAS but those of the other hybrids were vice versa. Rate of super-sweet kernels per ear of Chalok 1/Cocktail 51 corns was about 38 %. Development, and elongation of kernel were much more prominent in supersweet kernel than in waxy kernel, but fresh weight increased higher in waxy kernel than supersweet kernel. Moisture content in kernel decreased from 15 DAS to 35 DAS. Total sugar content of the kernel increased until 25 DAS, and that of Cocktail 51 kernel showed the highest among of them. After cooked by steam, flavor and mastication feeling rate cooked by steam of Cocktail 51 and Chalok 1/Cocktail 51 were increased from 15 DAS to 25 DAS and markedly decreased thereafter. But those of Chalok l/Cocktail 51 and, Chalok 1 were decreased after 30 DAS. These results suggested that the optimum harvest date for fresh supersweet corn (Cocktail 51), Cocktail 51/Chalok 1 seems to be about 20 DAS and Chalok 1/Cocktail 51 and waxy com (Chalok 1) was about 25 DAS.